THIRD YEAR DIPLOMA IN CIVIL ENGINEERING SUB-W.R.E

1. MINOR AND MICRO IRRIGATION
Prof.M.B Chougule DKTE’S Y.C.P
•

4. .
• Bandhara Irrigation
• It comes under minor irrigation project. (5 to 2000ha)
• Irrigation area and 5million rupees of expenditure.
• 1) The river or stream on which bandhara is going to be
constructed should be perennial.
• 2) The site should be within 5 km of the area to be
irrigated.
• 3) Good foundation should be available for
construction of bandhara.
• 4) Site should be such that it should provide irrigation
on both banks through canals from both sides.
• 5) Site should be just on upstream side of steep bed
slope.

5. .
• Bandhara Irrigation: Bandhara irrigation scheme is a
minor irrigation scheme in which direct irrigation is
practiced. The bandhara is a masonry diversion weir of
small height and the object is to raise water level in the
stream.
• The bandhara is a local name and in bandhara irrigation
a small barrier or a wall of small height is constructed
across the river or stream to raise water on U/S side.
• The main object of bandhara is ti raise water on
upstream side so that it can be diverted in canal on one
or both sides of bank
• It is type of direct irrigation.
• It serves the purpose of irrigation during long dry spell
in monsoon.

6. .
• Advantages of Bandhara Irrigation :
• 1) The system of irrigation is economical.
• 2) The irrigated area is compact and hence irrigation is intensive,
• length of canal is less, transit losses are also less, all these factors
lead
• to high duty of water.
• 1. 3) The water of small catchments which would otherwise have
gone
• waste is fully utilized.
• Disadvantages of Bandhara Irrigation :
• 1) As irrigable area is fixed if more water is available for irrigation it
• cannot be used.
• 2) There might be uncertainty of supply of water in case of non-
• Perennial River.
• 3) If number of bandhara is constructed on a stream downstream
• people may be adversely affected.

7. selection of a site for Bhandhara.
• 1) It should be near the area to be irrigated.
• 2) It should be preferably below the confluence of two or more streams
to have good supply of water.
• 3) It should be preferably be just on upstream side of steep bed slope.
• 5) Good foundation should be available for the construction of
bhandhara.
• 6) The cost of construction should be within yard stick(5000 per.ha)
• 7) The river or stream on which bandhara is going to be constructed
should be perennial.
• 8) The site should be within 5 km of the area to be irrigated.
• 9) The site should be located on straight reach of the stream, so that
canals can take off from both sides & irrigation can be provided on both
banks.
• 10) Good foundation should be available for construction of bandhara.
• 11) deep cutting should be avoided for canal.
• 12) less cultivable area is submerged on upstream side.

8. COMPONENT PARTS AND LAYOUT

9. COMPONENT PARTS
• 1) bandhara and scour hole.
• 2) the screen wall and outlet.
• 3) the flood bank.
• 4)canal and the lining wall. ( off taking canal)

10. bandhara and scour hole.
• The main two types of bandhara are:
• 1) solid bandhara
• 2) open bandhara
• The method of construction of permanent or pucca
bandhara is depend upon temporary or kaccha bandhara.
• Before construction of permanent or pucca bandhara is
constructed and if it is found suitable after its performance
it is replaced by pucca bandhara.
• Pucca bandhara is constructed in stone masonary, brick
masonry or either by concrete.
• The two type of pucca bandhara is solid and open
bandhara.
• The height of bandhara may vary from 2.5 to 3.5m. And top
width is between 3 to 4m.

11. .
• SCOUR HOLE:-
• These are holes of diameter 20 to 50 cm at a height of 30
to 50 cm above river bed across the solid wall.
• The main purpose of these holes are heavy and coarse silt
passes through these holes to the downstream side.
• These holes are closed after rainy season is over.

12. KOLHAPUR TYPE OR OPEN BANDHARA

16. .
• Location – This type of bandhara is commonly
constructed in Kolhapur district
• Function –
• To raise the water level on upstream side so that it can
be diverted in the canals on one side or both sides of
banks.
• Working - It is fully open weir. It consists of number of
piers & has side grooves for fixing wooden needles. The
needles are put across the piers for the required height
to form continuous weir. The height can be changed by
removing needles or putting additional needles.
Needles are removed during floods to avoid rise of
water on u/s.
• The needles is 15cm, height 5cm thick and 2mm length
• These needles are to be replaced in about 5 years time.

17. .
• This type of bandhara is commonly constructed in
Kolhapur district It is constructed to raise the water
level on upstream side so that it can be diverted in
the canals on one side or both sides of banks. It is
fully open weir. It consists of number of piers and
has side grooves for fixing wooden needles. The
needles are put across the piers for the required
height to form continuous weir. The height can be
changed by removing needles or putting additional
needles. Needles are removed during floods to
avoid rise of water on u/s.

18. .
• Construction : This type of bandhara is commonly
constructed in Kolhapur district & hence called K. T.
Weir. The sufficient openings are kept in nalla portion
so that there is no afflux. Masonry piers with regular
grooves are provided with standard opening of 2 m.
These openings are blocked by means of needles in
two rows filled with paddle in between them. The
needles are placed in the grooves provided in piers.
The size of wooden needle 15 cm high, 5 cm thick & 2
m in length. These wooden needles are placed into
the openings by the fag end of monsoon to store the
post monsoon water. It is necessary to restrict the
number of openings because of the consideration
difficulties involved each time in placing the wooden
needles at the fag end of the monsoon & removed of
them just before the monsoon.

19. .
• Operation: It is fully open weir. It consists of
number of piers & has side grooves for fixing
wooden needles. The needles are put across
the piers for the required height to form
continuous weir. The height can be changed
by removing needles or putting additional
needles. Needles are removed during floods
to avoid rise of water on u/s.

21. .
• TEMPORARY BANDHARA:-
• it is constructed by placing obstruction of any material
like stones, cut juncle, tree trunks with earth and stone,
swan verticals of wood with G.I. sheets facing etc.
• THE SCREEN WALL AND OUTLET:-
• It is the wall constructed on upstream side of bandhara
at an angle of 90 to 120 degree with outlet located in
this wall with a steel gate which can be operated from
the top of wall. The sill of opening is kept 0.3m below
FSL.
• THE FLOOD BANK :-
• these are earth embankment. These flood bank
protect the fields on outside of bandhara from drowing
under the back water created by bandhara.

24. Percolation Tank:-
• Percolation tanks are needed to raise the ground
water table in the command area. This increase in
water table leads to raising of water levels in wells
which helps in increasing lift irrigation. For reducing
evaporation loss of water & reducing cost of
irrigation,
• Necessity of Percolation tank :
• Percolation tanks are constructed on pervious soils
so that percolation of water takes place through
foundation soil and will be available on d/s in wells
for lift irrigation when required

30. .
• percolation tank differs from Irrigation tank.
• Percolation Tanks :- For percolation tank, the bed
should be pervious. They are constructed at suitable
site by providing earthen bunds. The water from it
percolates through the tank bed & joins the ground
water table. It raises the water level of the following
existing wells. The water is then pumped for irrigation.
Thus it is an indirect system of irrigation.
• Irrigation Tank :- For irrigation tank, the bed should be
impervious. It is constructed where the basin is
watertight. It is constructed on river where the narrow
valley portion is available. Water is stored on upstream
side of the dam & then it is released as per the
requirement for irrigation through canals. Thus it is
direct system of irrigation.

34. .
• construction of percolation tank
• Construction of percolation tank is as follows:- The only component
of these scheme is earthen bund may be in single or straight
alignment with cut off trench A cut off trench of 30 to 90 cm depth
and 60 to 120 cm bottom width which is constructed with locally
available material like moorum, soft rock, black cotton soil and stones
for chipping. The earthen bund consisting of sandy casing &clayee
hearting for retaining water on u/s side. The central core portion of
bund is compacted, properly by adding proper moisture and then
sandy type of soil is placed on this core as a cover with compaction
and upstream. Side is packed with boulders or stones. Riprap is
provided to protect the u/s slope of bund. Cut off trench is provided
at the centre of hearting in foundation of tank. height of bund will
not generally exceed the limit of 10m. The drainage arrangement
should be provided in the bund seat to avoid slips by saturation

36. .
• Advantages of percolation tank-
• 1. The total cost of project is low
• 2. The construction of bunds is simple and hence there is no need for
skilled labours machines etc.
• 3. The site which are unsuitable for other type of irrigation may suitable
for this type of scheme and thus better utilization of natural resources
can be made.
• 4. The irrigation benefits of the percolation tanks are indirect as no
irrigation outlet is provided for carrying out direct irrigation.
• Dis-advantages of percolation tank-
• 1. The area commanded by percolation tank is uncertain. The reason for
this is that the exact passage of water through the subsoil is not easy
and economical to locate.
• 2. The efficiency is very low
• 3. The dam may slip and fail due to seepage forces.
•
• For carrying out reliable investigation, no of trial pits are required in
entire command area as well as geological investigations are also
required to be carried out which increases the cost.

37. .
• site for construction of percolation tanks.
• 1) The percolation tanks are constructed where soil is porous
and it is not possible to construct the big retaining structures.
• 2) In percolation tank water percolate through soil pores and
joins the ground water which increases water level in wells on
downstream side.
• 3) Thus percolation tanks are suitable where there are more
number of wells and bore wells.
• 4) Useful in areas where other water retaining structures
cannot be constructed.
• 5) The bed of tank should be pervious so that water will
percolate and join ground water.
• 6) The site at which bunds are constructed should have
sufficient discharge.
• 7) The side of stream should be steep.
• 8) for construction the material and labour should be
available nearby the site.

38. .
• LIFT IRRIGATION:-
• When the source of water is lower than the area to be
irrigated, then water is to be lifted by artificial means and
process of lifting water from lower to higher level is called
as lift irrigation.
• This situation occurs when the area to be irrigated is at
higher level than canal or reservoir. When mearly through
gravity, it is not possible to divert flow of water to irrigable
land similarly on higher banks of contour canal the area can
not be irrigated by gravity. In such cases lift irrigation
system in installed.

42. .
• ADVANTAGES OF LIFT IRRIGATION SYSTEM:
• 1) the optimum use of water is achieved and thus increases
efficiency.
• 2) isolated development is possible as more people get
advantage from irrigation.
• 3) lifting of water from well and tube wells helps to lower the
ground water table and thus avoids water logging.
• 4) as it is operated manually farmers can utilized water in
proper manner and thus optimum use of water is achieved.
• 5) the water from much below ground is also utilized for
irrigation purposes and thus helps in proper utilization of
resource is achieved.
• 6) on small case where area to be irrigated to small extent
farmers can dug a bore and at just rupees 15 to 20 thousand
only and hence its initial investment is low.

43. .
• DISADVANTAGE:-
• 1) if irrigation is particularly from well it may conation
harmful salt, which is harmful to crop.
• 2) the pumping units may require frequent
maintenance and thus increases cost of scheme and
lead to scheme uneconomical.
• 3) the working of pumps depends on power and its
mechanical maintenance. Failure of lifting devices
cause harm and farmers has to depend on some other
persons and hence dependabity is less.
• 4) if water is lifted from well it is always clear water
with no organic matter and thus its fertilizing value is
nil hence requirement of manure increases if well
water is used.
• 5) discharge from well is less as compare to canal,
which is suitable only for small areas.

44. .
NECESSITY OF LIFT IRRIGATION:-
1) Where the areas are left out of canal irrigation due
to their high elevation.
2) in areas where rain fall is uncertain and inadquate.
3) where source of water is lower than area to be
irrigated.
LIFTING OF WATER FROM RIVER:-
In this type water is lifted from river by the pump.
Here source of water is river, pumps are installed on
the banks where sufficient supply is available and
then it is lifted and is supplied to irrigable land.

45. .
• LIFTING OF WATER FROM CANAL:-
• in this case source of water is canal and water is
lifted through pups to the required elevation and
then allows to flow in fields through gravity.
• LIFTING OF WATER FROM WELL:
• When the source is well then lift irrigation scheme
is called as well irrigation. The components of well
irrigation system are:
• 1) well
• 2) lifting devices
• 3) the distribution system

46. .
• FEATURES/ COMPONENT PARTS OF LIFT IRRIGATING
• (1) Intake channel.
• (2) Inlet chamber
• (3) Jack well
• (4) Inlet pipe joining inlet chamber
• (5) Engine house
• (6) Rising main
• (7) Delivery chamber
• (8) Water distribution system
• (9) Pumping machinery.

48. .
• 1) Intake well: A channel is constructed for diverting the flow of water to
inlet chamber.
• 2) Inlet chamber: It avoids silts and debris to enter into jack well.
• 3) Jack well: It is provided to facilitate location of an engine house above
high flood level and allows pumping during floods.
• 4) Inlet pipe: To convey water from inlet chamber to jack well and inlet pipe
is provided with proper gradient.
• 5)Engine House: It is small storage room which accommodates the engine
and pumps to be installed.
• 6) Rising main: It is a delivery pipe which transmits water from well to
delivery chamber.
• 7) Delivery chamber: The water from rising main is collected in delivery
chamber and then it is allowed to flow in field ditches.
• 8) Water distribution system: It is the system which distribute water from
delivery chamber to field channel.
• 9) pumping machinery: the design of pump should be according to be
made. Generally 3 pumps are installed for design discharge.
• ECONOMY:-It is not economical as cost in lifting water is more. as compared
to recovery from cultivator
• But it is used to develop solid economic condition and used where no other
sources of irrigation water

49. .
• SELECTION OF PUMPS
• 1) axial flow pumps 2) centrifugal pumps
• 3) reciprocating pumps 4) vertical turbine pumps
• THE SELECTION OF PUPM DEPENDS UPON:-
• 1) total lift 7) permissible suction
• 2) speed of pump 8) total head
• 3) cost of unit power 9) quality of water
• 4) monthly demand pattern
• 5) temperature 10) sediment content
• 6) maximum discharge
• 7) water surface level difference i.e. intake &
discharge

50. .
• POINTS TO BE CONSIDERED WHILE DESIGN OF LIFT
FROM CANAL:-
• 1) the lift canals must be lined to reduce seepage
losses and flat bed slope is provided as steeper the
slope more will be drop which requires greater lift
and increases pumping cost.
• 2) the due consideration should be given to the
sizes of sand particles may affect working of
machine i.e. pumping unit.
• 3) the value of silt for canal lift should kept lower
than canal from which water is lifted its value
should range in between 0.75 to 0.80m

52. `

53. .
• advantages of lift irrigation over surface irrigation.
• 1) Farmers can irrigate their field as per.
requirement and they have control on supply.
• 2) Optimum use of water is possible.
• 3) Lift irrigation reduces chances of water logging.
• 4) It can be implemented at any desired place.

54. .
• IRRIGATION DEPARTMENT STANDARD DESIGN AND
SPECIFICATION DESIGN CRITERIA:
• 1) source of water supply should be reliable and dependable.
• 2) suitable site for the construction of intake well should be available
in the river bed.
• 3) necessary arrangement should be made to prevent the entry of
floating matter and silt into the well.
• 4) even in the dry or lean season, there should be sufficient amount
of water entering into the intake well.
• 5) the level of the inlet pipe conveying water from intake well to the
jack well should be above the silt level in the intake well i.e. It should
allow to flow silt free water from intake well to the jack well by
gravity
• 6) the diameter of the inlet pipe should be sufficiently large ( greater
than 450mm) to avoid choking of the pipe due to silt etc.
• 7)the jack well should be installed at such a place that under no
circumstance it is flood by the water. i.e. This weir should be located
such that its top is above the high flood level of river.

55. .
• 8) there should be continent access to the jack well through out year
• 9) it should be possible to install the pumping unit on the top of jack
well without difficulty.
• 10) a square shape pumping unit is to be preferred to the circular
one. The total gross head (H) will equal to the difference in level.
• 11) the static suction head usually varies from 3 to 4m and the total
suction head is to be limited to 8m. The delivery end of the pipe
should be suitable connected to the rising main by one or more y
junctions.
• 12)proper arrangement of a sluice and a reflux valves is to be
regulate the discharge and to avoid removal of water from the main
rising main.
• 13) the appropriate size( i.e. Diameter) of raising main should be
selected for given discharge.
• 14) the type of pipe is of required thickness.
• 15) usually the rising main is buried underground with proper cover.
• 16) the water from the delivery chamber should flow into the
distribution system by gravity.

56. SPRINKLER IRRIGATION SYSTEM:-
• With the help of sprinkler irrigation system, water is
applied over the land surface in the form of spray. It
is also called as overhead irrigation.
• Need or necessity: Sprinkler irrigation is best suited
for very light soils as percolation losses at higher
depth are prevented. This irrigation method can be
used for all the crops but not suitable for the crops
like rice, jute, sugarcane, jawar etc. for which
standing water is required. This method is more
flexible to suit undulating topography, therefore
levelling for land is not necessary. It is quite suitable
for lawns in the garden; small height crops etc
•

60. .
• Need of sprinkler irrigation:
• 1. Where water requirement of crop is less.
• 2. Where slopes are excessive.
• 3. Where soil is erosive.
• 4. Where soil is excessively permeable.
• 5. Where depth of soil is shallow.

61. .
• :-sprinkler irrigation:-sprinkler irrigation refer to application
of water to crops in form of spray from above the crop like
rain it is also called as overhead irrigation .In this method
water under pressure is carried and sprayed into the air above
the crop through a system of overhead perforated pipes
,nozzle lines or through nozzle fitted to riser pipes attached to
a system of pipe laid on the ground .Nozzles may be fixed
type or rotating under the water pressure.
• Situation :Sprinkler irrigation may be used for many crops
and on all type of soil on lands of different topography and
slopes.
• It is best useful to sandy soil and soil with high infiltration
rates
• It is applicable for are with steep slopes having erosion
hazards.
• The operating and maintenance cost is high.
• It is suitable for growing high priced

62. Layout of Sprinkler Irrigation System

63. COMPONENT PARTS AND IS FUNCTION:-
• PUMPING UNIT:- with the help of pumping unit, water is
pumped under pressure to the fields through sprinklers or through
perforations or nozzles made in pipeline in the form of spray.
• High speed centrifugal or turbine pump can be used for the purpose
of operating the sprinkler irrigation system.
• TURBINGS:- it consist of machine, sub lines an lateral main line
carry water from the source and distribute it to the sub mains which
further convey water to the laterals, laterals turn the water supply to
the sprinklers, now-a-days, PVC pipe are mostly used for sprinkler
system.
• COUPLERS:- couplers can be used for connecting two pipes and
uncoupling rapidly and easily.
• SPRINKLER HEAD:- it is must important component. It
distribute the water uniformly on field without any loss( runoff)

64. .
• FITTINGS AND ACCESSORIES:-
• 1) water meter: it measure the volume of water delivered.
• 2) flange, couplings and nipple: these are used for the proper connection
to the pump, suction and delivery.
• 3) bend, tees, reducers, elbows, hydrants, plugs and butterfly valve are the
various fitting units used in the sprinkler system.
• 4) pressure gauge: it controls water pressure and hence it is used to know
whether the sprinkler system is working under required pressured or not.
• MAINTENANCE:-
• 1) keep all nuts and bolts tight.
• 2) clean any dirt silt or sand out of the groove in the coupler frequently
because any accumulation of dirt, silt or sand affects over the performance
of the rubber sealing ring.
• 3) fertilizer bags should not laid on the pipe.
• 4) when moving the sprinkler line, make sure that sprinklers are not
damaged or pushed into the soil.
• 5) any oil or grease or lubricant should not apply to the sprinklers.

65. .
• 6) check the washer for wear once a season or every six month and
replace the washer if it worn.
• 7) after several seasons operations, the swing arm may need
tightening and it can be done by pulling out the spring and at the top
and rebending it.
• 8) sprinkler equipment should be kept in a cool and dry place during
the off season.
• OPERATION:-
• the pumps lifts the water from the source like water tank, reservoir
etc.
• Supply the water through the pipe to the sprinklers from which the
spray of water is developed and spread over the land surface.

66. .
• Merits of sprinkler irrigation –
• 1) Erosion of land can be minimized.
• 2) Uniform application of water is possible
• 3) Leveling of land is not required.
• 4) Elimination of seepage & percolation losses thus prevent water logging.
• 5) Fertilizers can be applied in solution form along with irrigation water from the
sprinklers.
• 6) This method stimulates the rainfall conditions & its efficiency ranges from 80 to
90 %.
• 7) More land is available for irrigation as borders, ditches etc. are minimized.
• 8) Small streams of irrigation water can be used effectively.
• 9) It is standby pumping set
•
• Demerits of sprinkler irrigation –
• 1) Uniformity of irrigation is not achieved when wind velocity is more than 16
km/hour.
• 2) Initial cost of sprinkler set is high.
• 3) Sprinklers are not suited for crops requiring frequent large depth of irrigation as
in case of banana, paddy etc.
• 4) A constant supply of water is needed for economical use of equipment.
• 5) Water must be clean & free from sand etc.
• 6) The power requirement is high

67. .
• Trouble Shooting in Sprinkler irrigation system:
• a) Pump does not prime or develop pressure.
• b) Sprinkler does not rotate.
• c) Leakage from coupler or fittings.
• d) Sand particles if present may offset irrigation.
• e) Perforated pipe laid on ground may get choked.

68. .
• Mention four advantages of sprinkler irrigation over
canal irrigation.
• Following are the four advantages of sprinkler irrigation
over canal irrigation :
• 1) Erosion of land can be controlled.
• 2) Uniform application of water is possible.
• 3) Irrigation is better controlled.
• 4) Land preparation is not required, hence labor cost is
reduced.
• 5) Small streams of irrigation water can be used
efficiently.
• 6) Fertilizers can be applied in solution form along with
irrigation water from the sprinkler.
• 7) Elimination of seepage & percolation losses thus
prevents water logging.

69. .
• drip irrigation:-
• Importance of drip irrigation:-Drip irrigation is the application of
water at a slow rate drop by drop through ,perforations in pipe to
irrigate limited area around the plant.
• A precise amount of water which is required by the plant is given .in
drip irrigation. deep percolation losses and evaporation losses are
reduce .This method very useful in arid regions where water is scarce
.It enables application of fertilizers along with importance of
irrigation water. it ensure s optimum growth ,better fruiting and more
growth of crops with optimum quantity of water .it is more applicable
to variety of row crops from widely spaced fruit crops to closely
spaced vegetable crops.
• It saves the water and fertilizer by allowing water to drip slowly to the
root of the plants. In water scarcity zones, this system is much useful.
There is no wastage of water in this system. It is most suitable for row
crops

70. drip irrigation system
• It is method of irrigation in which water is dropped slowly to the roots of
the plants, either onto the soil surface or directly onto the root zone
through a network of valves, pipes, tubing and emitters. Drip irrigation is
also termed as micro irrigation or trickle irrigation or localized irrigation.
• Need of drip irrigation :
• 1) It saves the water and fertilizer by allowing water to drip slowly to the
root of the plants.
• 2) In water scarcity zones, this system is much useful.
• 3) There is no wastage of water in this system.
• 4) It is most suitable for row crops
• Components of drip irrigation:
• 1) Pump unit
• 2) Control head
• 3) Main, sub main lines and laterals
• 4) Drippers or emitters

74. .
• 1. Pump unit :It conveys the water from the source and provides the
pressure for delivery into the pipe system.
• 2. Control head or control valves :Control head is made of valves.
• These valves control the discharge and pressure of water in the
• complete system. It also consists of filters which clear the water.
• 3. Mainlines, submains and laterals :Water is pumped from source
and conveyed to the fields from the control head through mainlines,
submains and laterals. Mainlines, submains and laterals are generally
made in PVC or polythylene hose which buried below ground.
• 4. Emitters or Drippers: It is a device by which the discharge of
• water from lateral to the plants can be controlled. Emitters are
• generally spaced more than 1m apart with one or more emitters.

75. .
• LAY OUT OF DRIP IRRIGATION SYSTEM:-

76. Maintenance:-
• emitters are prone to clogging from deposits of calcium carbonate,
algae or bacteria, so drip irrigation requires maintenance for better
performance and service.
• 1) drip system should be flushed checked every day and cleaned if
necessary.
• 2) drip lines should be flushed with acid at the end of each season to
remove the precipitation of calcium and magnesium salts.
• 3) if there is already a lot of algae and bacteria growing in the
pipeline, then emitters can be plugged worse it is very important to
flush the lines extensively before irrigating again.
• 4)inspect drippers, micro sprinklers and micro tubing periodically to
ensure that no dripper is clogged.
• 5) filter screen should also be flushed and cleaned at least once in
month depending upon the water quality.
• 6) drip tubing should also be flushed periodically.

77. .
• 7) during freezing weather, it is recommended to remove
the battery operated controller for the season.
• 8) remove end caps or open hose ends to flush the line
once a year.
• 9) during freezing weather, it is recommended to drain poly
tubes or rolling it up or storing it.
• 10) remove the filter body and check the screen at the end
of first week. If the screen is clean, check the filter each
month. If there is no dirt at the end of a month, then clean
the filter once per season.
• 11) once a week, walk along drip irrigation system, when it
is on and look to make sure that water is flowing at each
dripper. If dripper is not working , replace it.

78. .
• advantages of Drip Irrigation.
• Following are the different advantages of drip irrigation :-
• 1) This method eliminates evaporation losses which are prominent in
sprinkler & surface irrigation.
• 2) As compared to surface irrigation this method needs nearly 25 % water
to mature a crop.
• 3) Frequent ploughing is not required as the surface does not become hard.
• 4) Though this method is more expensive than sprinkler system, but it is the
best method of irrigation with ground water in arid zones where soils are of
poor structure & have high salt contents.
• 5) In this system of irrigation, water deficit in the soil never occurs.
• 6) Due to constant wetting of the soil around the root zone, the high
concentration of salts in the root zone does not occur.
• 7) This method has been found to be very useful in reclaiming & developing
desert area.
• 8) Experiments have shown that the yield of crops due to this system has
increased substantially & in some cases even more than double yield has
been obtained in comparison to other methods of irrigation.